Read the passage and answer the questions.



Malware refers to a group of computer programs designed to work against the requirements of a user’s computer for the purposes of causing harm. Those who spread malware are called “hackers.” There are several different classes of malware. Malware is a significant problem throughout the world resulting in billions of dollars in damages to individuals and businesses every year. Below is a summary of some of the most common forms of malware.




These are computer programs that replicate and modify other programs by inserting code. Viruses typically target individual computers.




A worm is a malicious program that replicates itself in order to spread to other computers, often in a single network. Worms target groups of connected computers on a network.


Trojan Horse


A Trojan horse is a malicious program designed to trick a user about its true intent. Trojan horses typically show up in e-mail attachments or drive-by downloads. They often create “backdoors” which allows the creator unauthorized access to a user’s computer.




Ransomware is a malicious program that encrypts the files on a user’s computer so they are unreadable. These files can only be retrieved if the user agrees to pay a ransom (usually in Bitcoin) within a specified amount of time to obtain a decryption key. Decryption without the key is impossible.




Spyware is a type of malicious program covertly installed on a user’s computer to collect important information such as credit card numbers or passwords.




Scareware is a type of malicious program designed to scare people into buying unwanted programs such as anti-virus software. Scareware typically comes in the form of warnings or alerts that the user’s computer is infected with a virus and the purchase of software is the only way to save the computer.